[Determination of total and inorganic phosphorus in the presence of organic phosphoric acid esters and proteins].

Total phosphorus was estimated after mineralization of a sample, containing organic phosphoesters and proteins; a method is based on the formation of phosphomolybdenovanadium complex at acid pH. The analyses for inorganic phosphorus were carried our together with estimation if some labile phosphoesters (glucose-I-phosphate, ADP, ATP), which was possible due to low acidity of the medium (0.24 N HC1O4), small concentrations of reagents (3.2 mg/ml of molybdate, 0.08 mg/ml vanadate), addition of sodium citrate to neutralize the excess of molybdenovanadium acid and extraction of the colored complex with butyl or isobutyl alcohol. Optical density was measured at two wave lengths (340 nm and 390 nm) which enabled to estimate from 0.5 to 80 microng of phosphrorus in a sample.